West Texas
Sunflower
Insects
Ed Bynum1 and Calvin Trostle2
Texas A&M AgriLife Extension Service
1Extension
Entomologist, Amarillo, TX (806) 677-5600,
ebynum@ag.tamu.edu
2Extension Agronomist, Lubbock, TX (806) 746-6101,
ctrostle@ag.tamu.edu
Sunflower Production in Pictures
Some of the most important things you
need to know about sunflower production
in Texas
And Ultimately
Rhizopus Headrot
“Styrofoam
Bricks!”
Are these pictures worrisome?
Don’t let them be—just be informed
The good news is that the sunflower moth is
manageable—We know:
How to scout (if we don’t just automatically spray,
our apologies to IPM practices)
When to spray
What to use
To follow up to ensure the first spray is OK
This just happens to be a major downfall of too
many inexperienced, first time, or “a-couple-ofdays-too-late” growers
Easy Way to Ruin Sunflower
In our experience this is the #1 problem
in Texas sunflower production
Stated a different way, the most likely
stumbling block that turns a decent crop
into something sub-optimal, and in worst
cases, a failure
The “Boll Weevil of
Sunflowers”—Sunflower
Moth
Too many growers “never knew” about
this insect before growing, or if they did
they sprayed too late—It will lead to
major crop damage if not controlled.
The moth you scout for—
early dawn or nearly dark!
The larvae feeding which
leads to fungal infection.
Rapid Progression of Bloom
Hybrid
Planted
--- % of Bloom --8/13
8/15
8/17
Triumph 845HO
6/26/07
0
5
68
Red River 2215
6/26/07
1
9
84
7/11
7/13
7/15
Triumph 845HO
5/17/08
1
23
96
Red River 2215
5/17/08
0
10
74
Example of Larval Abundance
(no spraying)
Mean Number of SFM Larvae/Head
Days After 1st
Bloom
Field 1
Field 2
Field 3
Field 4
3
0
2
1
0
6
3
0
3
9
9
7
27
2
77
12
38
15
4
220
15
34
28
3
263
18
28
18
3
312
21
13
24
7
215
24
8
23
47
142
27
4
12
71
77
30
---
12
75
---
33
---
13
---
---
Sunflower Moth Spraying
“Managing Insect Pests of Texas
Sunflower,” Texas AgriLife Extension
Service, E-579 (2009)
http://agrilifebookstore.org for
view/print/download color copy
Sunflower moth treatment strategies
Historical ‘By the Book’ suggestions
Current ‘By the Book’ suggestions
Industry recommendations & practices
Sunflower Moth Spraying
Historically “By the Book” – 1998 Texas Guide
Spray @ 20% - 25% bloom when any moths are
found in the field – Count any head as blooming
when any part of the flower is exposed.
Apply first pyrethroid (possibly with methyl parathion
for added quick knock down) @ 20-25% of plants in
bloom
Downside: Have to be scouting early, No room for
error; practice tolerated significant level of moths in
the field; moths have 1-2 days to freely lay eggs
Result: Applications not timed right then producers
are likely to have damage?
Sunflower Moth Spraying
Current “By the Book” (Extension’s insect guide)
Spray at 15-25% bloom ‘when moths are in the
field’, Count any head as blooming when any of the
ray flowers are opening and disk flowers are
exposed.
No statement on how many moths (threshold is
presence, not number)
Apply first pyrethroid (possibly with added methyl
parathion for quick knock down)
Downside: Still no room for error; moths still have 12 days to freely lay eggs on many heads
Result: Still have potentially damage if late
Sunflower Moth Spraying
Industry practices & recommendations #1
Spraying earlier (~5% bloom, i.e. 1-2 days earlier) &
lower moth threshold—this minimizes mistakes, may
provide better results, allows room for delayed spraying
Makes the spraying decision sooner (which allows more
time to schedule spraying)
Downside: Could you spray too early? If you spray this
early, would you lack chemical residue in 5-7 days, or be
forced to spray a second time (esp. dryland)?
Result: No method is immune to failure, but industry
widely believes this approach offers protection against
common pitfalls (spraying too late, more time to act if it
appears first spray was not effective), possible better
control
Sunflower Moth Spraying
Industry practices & recommendations #2
Spraying earlier and automatically (~5% bloom, i.e.
1-2 days earlier)
Makes the spraying decision sooner (which allows
more time to schedule spraying)
Downside: Again, could you spray too early, and
lack chemical residue later? Did you in fact need to
spray, especially for late-planted sunflower (thereby
an unnecessary expense)? It is wise to still know
what level of moth was in the field (might influence
decision on whether to spray a second time)
Result: No method is immune to failure, but at least
you can’t say you didn’t spray.
Hybrid trial with bloom ranging
from 0% (upper right) to 20-25%
(center back). Using (latest R4/initial R-5.0) bloom, the field is
>5% in bloom as a whole.
This head is considered blooming
Calvin Trostle/Pat Porter, Texas A&M AgriLife Extension Service
Sunflower Moth Spraying & IPM
Is it unthinkable to suggest we’d spray
sunflower for sunflower moth without scouting
However, industry experience suggests that as a
group we might be better off if we sprayed
automatically because of the mistakes that can
occur
It is commonly thought “If you have head
damage it means you sprayed too late”
This discounts that truly sometimes a spray doesn’t
work
Or the moth flight was late
New Insecticide, New
Approach—Prevathon, 2013 I.
 Active ingredient, chlorantraniliprole (Rynaxypyr), from
Dupont
 “Softer” chemical; does not affect honeybees and other
beneficials
 See supplemental label for further information
 Ignore label’s minimum 2 gallons water per acre, go with
at least 3 gpa, preferably 4
New Insecticide, New
Approach—Prevathon, 2013 II.
 “Translaminar” movement of insecticide to feeding larvae
Little to no activity on adults so scouting after your first spray
doesn’t mean much
 10 to 14-day spray interval (though supplemental label
says 7 days, use MSO additive)
Extension & Dupont agreement, December 2013: initial spray of
14 oz/A at 1% bloom and then 14 oz./A again in 7-10 days (a
single initial 20 oz./A application may not be enough)
New Insecticide, New
Approach—Prevathon, 2013 III.
 See the special label for Texas at http://www.cdms.net
 First spray earlier (initial bloom) than pyrethroid alone
(5-20% bloom)
 Initial data compared to pyrethroid, which kills
beneficials, demonstrates lower larval counts in the
head for Prevathon
 First impression from Texas A&M AgriLife Extension
entomologists: results are good, mixed thoughts on
excluding pyrethroid until more data is collected
Besiege, from Syngenta, is a mix of Rynaypyr (different
formulation) and pyrethroid
New Insecticide, New
Approach—Besiege, 2013
 Syngenta—mix of chlorantraniliprole and pyrethroid
(Lambda-cyhalothrin), 6-10 oz/A
 See the special label for sunflower at
http://www.cdms.net
 First spray “before pests reach damaging levels”
 Chlorotraniliprole in Prevathon: 10 oz./A rate of
Prevathon = 7.6 oz/A for Besiege
A 14 oz./A rate of chlorotrniliprole would be 10.6 oz./A of
Besiege, which is a little high
This rate of Besiege @ 7.6 oz./A includes 1.54 oz/A of Warrior
II/L-cyhalothrin (labeled range for sunflower, 1.28-1.92 oz./A)
New Insecticide, New
Approach—Belt (Bayer), 2013
 First spray same time as pyrethroid
 Like Prevathon, this does not kill adults either, but kills
young feeding larvae; does not have movement within
the plant
 Ignore label’s minimum 2 gallons water per acre, go
with at least 3 gpa, preferably 4
 First impression from Texas A&M AgriLife Extension
entomologists: results are good, mixed thoughts on
excluding pyrethroid until more data is collected
Limited data suggests good control, reduction in feeding larvae
Bottom Line—Sunflower Moth
 Whatever approach you choose:
1) Do your best to achieve uniform emergence, hence
uniform bloom
2) Two weeks prior to probable spray, get a
commitment from applicator and make sure
chemicals are on hand
3) Do scout at first bloom anywhere in the field (if
you are a first-time grower, get help)
4) Aerial spray—minimum 3 gal/A, hopefully a little
more
5) Follow-up scouting a from 3 - 4 days after first
spray to ensure you get kill to know if moths are
still present
Frank Discussion on
Sunflower Moth Spray Timing
 Our AgriLife recommendations (for pyrethroids?) in and of
themselves are OK, but you must scout early and be prepared
to spray, if you are ready then YOU CAN GET IT DONE AT THE
RIGHT TIME (THE NEXT DAY?) and get good control.
 Too many farmers don’t take time to scout/spray in time
 Although this violates what we know and believe about
Integrated Pest Management (IPM), collectively as a group,
farmers may be better off is spraying automatic-ally even if
only a few scattered moths are observed.
 Scouting in the heat of the day is not reliable for moth
populations between few and moderate. They hide on the
leaves rather than up on the heads as during pre-dawn and
late dusk.
 A limitation of AgriLife recommendations is people have not
understood that a bloom head is at the latest R-4 stage and
not the R-5.1 stage. When we use the late R-4 stage then the
15 to 25% bloom can in fact be closer to the 5 to 10% bloom
using the R5.1 stage.
Sunflower Moth Larval Damage
This is especially detrimental
to confectionary.
Upper left, R-3, will soon reveal back
side of ray petals (above, R-4), then
with ray petals open the next day (left,
R-5.1) will begin physiological bloom
around the edge of the face.
This picture sequence is about 7-9
days.
“Managing Insect Pests in
Texas Sunflower,” Dr. Ed
Bynum, Texas AgriLife
Extension—Amarillo
(2009)
Other Insects in TX Sunflower
Soybean stem borer in sunflower (Dectes
texanus Leconte); adult is Longhorn
beetle; also known as sunflower stem
borer or sunflower stalk girdler
Stem weevil
Stem Borer (D. texanus)
Occasional high incidence (e.g., 2001);
often not noticed until plants lodge
Egg laying near petioles, single larvae
burrows in pith, often found late in season
in base of plant
Girdles plant at soil line from inside out;
backfills bore hole with plant fibers, frass
Adult Long-horn beetle
(Dectes texanus)
This is the soybean stem borer larvae, about ¾”, maybe 1”
long that girdles the sunflower stalk from the inside out,
leaving a neat cut or break. Rarely ever more than one per
plant.
Stem Borer (D. texanus)
No pheromone traps, hard to scout, no
control recommendations at this time
Incidence appears higher near/after
soybeans enough that we don’t
recommend soy after sunflower or vice
versa
Observations suggest lodging potential
increases with higher plant populations
Be ready to harvest
Stem Weevil
Diverse observations on this being a
problem
National Sunflower Association annual
surveys haven’t shown much activity
Seed company production finds this to be
a common problem
Furadan no longer available for control
Seed treatments are not effective
SW larval rates drop significantly after
mid June planting dates – (Carl Patrick,
retired AgriLife Extension entomologist)
Other Misc. Items
Red/gray seed weevil?
Banded sunflower moth?
Many companies now treat all hybrids
with CruiserMaxx; Bayer also uses a
package of treatments (can’t remember
their insecticide)
Seed Treatments
Gaucho, Poncho, CruiserMaxx (which also
includes fungicide)
The latter two can add significant cost to
seed
Generally 45 days of protection is about
the limit of expected protection
?Some protection from wireworms but not
carrot beetle